(a) Field of the Invention
The present invention relates to LED projector lamps and more particularly to such an LED projector lamp that is equipped with an improved structure of radiation fins that have light shades constituting a light shielding wall to prevent light leakage and access of flies and vermin to the inside of the heat sink base thereof.
(b) Description of the Prior Art
Commercial LED (light emitting diode) projector lamps have a low power consumption characteristic. However, the working temperature of the LEDs of an LED projector lamp is limited to a small temperature range. Heat dissipation is quite important to an LED projector lamp. Conventional LED projector lamps commonly use a heat sink base for holding the LED light source. The heat sink bases of conventional LED projector lamps are common cast from metal. These metal heat sink bases are heavy and expensive.
Further, in order to enhance heat dissipation, radiation fins may be used in LED projector lamps and attached radially around the cylindrical heat sink base for quick dissipation of waste heat from the plurality of light emitting diodes of the light source that is bonded to the bottom wall of the heat sink base.
FIG. 6 shows an LED projector lamp with radiation fins according to the prior art. According to this design, a gap A is left between every two adjacent radiation fins 10. The heat sink base 20 shields a part of upward light during operation of the LED projector lamp. However, a part of upward light leaks through the gap A between every two adjacent radiation fins 10. Further, dust, flies and vermin may enter the inside of the heat sink base through the gap A between adjacent radiation fins 10.
Further, the aforesaid radiation fins 10 are thin metal sheet members, the sharp outer edge of each of the radiation fins 10 may injure the user's hands accidentally. Therefore, an improvement in this regard is necessary.